This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Background: We proposed to establish the efficacy MIV-160 alone against simian human immunodeficiency virus containing the reverse transcriptase gene of HIV-1 (SHIV-RT). Six animals were used for this experiment. Methods: Three (3) ml of MIV-160, 500[unreadable]M/ml in hydroxymethycellulose (HEC) gel was applied vaginal into 6 adult Indian female macaques. Half -hour post gel application, each animal was challenged vaginally with 1 ml high dose 10000 TCID50 of SHIV-RT. Again, 2 ml each of MIV-160 was applied vaginally in the respective animals. 30 minutes post SHIV-RT challenge. Results/Discussion: All animals were infected. MIV-160 failed to impede transmission of the impute virus. All animals had high viral set points which indicate that MIV-160 did not alter nor attenuate SHIV-RT.